Solid-state imagers typically comprise an array of pixel cells. Each pixel cell may contain one or more photosensors, which may comprise phototransistors, photoconductors, and/or photodiodes having stored charge in a diffusion region with a magnitude relative to the intensity of light received by the photosensor.
Each pixel cell may receive light focused through one or more microlenses. As the pixel cells decrease in size, the radius of each microlens may decrease. Manufacturing defects in the microlens can result in non-uniform or even blocked photosensors. Considering that the size of the microlenses are currently on the order of 3 μm or smaller, it is therefore increasingly important to reduce the number of lens defects as part of the manufacturing process. Reducing defects may increase fabrication yields, resulting in reduced pricing and improved market share.